15: Ruminant Nutrition 3

Biggest production concern with decreased nutrition

Reduced and less efficient production → lost money

What physiological system is the first to go when there is poor nutrition

Reproduction

Bloat pathology

Gas accumulation in rumen

Escalating effects of bloat

Increased thoracic pressure → resp distress → death

Types of bloat

• Free gas bloat

• Frothy bloat

Free gas bloat

Air bubble on top of rumen fluid

Nutritional cause of free gas bloat

Sudden increase in concentrates

How do concentrates cause free gas bloat

Sudden change → rapid fermentation → LOTS of acid → drop in pH → shift to lactate producers → lower drop in pH → less rumen motility → less eructation

Frothy bloat

Gas trapped in a stable froth

Nutritional cause of frothy bloat

High legume feed

How do legumes cause frothy bloat

Small particle size and high solubility of protein contributes to microbial production of mucoprotein slime that traps gas and prevents normal eructation

Types of ruminal acidosis

• Acute

• Subacute (SARA)

Cause of acute ruminal acidosis

Overfeeding concentrates

How do concentrates cause acidosis

Lots of concentrates → more lactobacilli → more lactate → more acid

Systemic effects caused by ruminal acidosis

• Dehydration: increased rumen osmolality pulls fluid into rumen

• Lower motility: due to low pH

• Systemic acidosis: acid absorbs across ruminal wall

• Anaerobic tissue metabolism

• Clinical laminitis

Effects of SARA

• Decreased DMI

• Subclinical laminitis

Symptoms of subclinical laminitis

• Sole ulcers

• Toe ulcers

• White line disease